144 research outputs found

    Magnesium - distribution and basic metabolism

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    Magnesium is extensively distributed in soil, water and plants. It is essential for ehzymatic reactions requiring adenosine triphosphate, and the recommended dietary allowance in man is 5 - 10 mg/kg/d. About 50% of magnesium in man is stored in bone, where it is regulated by parathyroid hormone'and 1,25(OH)2-D3. Most of the remaining magnesium pool is intracellular, plasma magnesium accounting for less than 0,5% of the total

    Behaviour of the descendent of cuban creole pigs

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    The present work was proposed to study the behaviour of the Cuban’s pig descendent derived of 27 sow and 5 boar and yours descendent from 93 calving. The animals were exploration by intensive system with lower quality supplements and sweet by sugarcane. The reproductive method utilised was the assisted mount. The results from piglets was: 7.52 total piglet was born; 6.77 piglets was born live; 6.42 weaning piglets; 0.912 kg means of the weight piglets was born live and 6.42 means of piglets weaning. The means of the Cubans Pigs observed in this study was similar with others Cuban and Spanish authors that study this kind of animals. There are differences between the Cubans Pigs and Iberians Pigs, were the Iberians Pigs showed the best weight was born.En este trabajo se estudiĂł el comportamiento de las descendencias de un rebaño de cerdos Criollos Cubanos en pureza, formado por 27 cerdas y 5 sementales y sus descendencias procedentes de 93 partos, explotados en un sistema de crianza estabulado y con un rĂ©gimen de alimentaciĂłn basĂĄndose en pienso B de baja calidad y suplementados con mieles de caña de azĂșcar. El mĂ©todo reproductivo empleado fue la monta dirigida. Los resultados del comportamiento de algunos indicadores de camada fueron los siguientes: total de crĂ­as nacidas, 7,52; crĂ­as nacidas vivas, 6,77; crĂ­as destetadas, 6,42; peso promedio de las crĂ­as al nacer 0,912 kg y peso promedio de las crĂ­as al destete, 6,03 kg. En cuanto al comportamiento medio de las crĂ­as nacidas vivas y destetadas se corresponde con reportes de otros autores cubanos que estudian el Cerdo Criollo Cubano y con autores españoles respecto a las variedades del IbĂ©rico. Las diferencias con los animales de este tronco se aprecian al comparar los pesos al nacimiento y a los 30 dĂ­as de edad, donde el Criollo Cubano se ve superado por las distintas variedades de animales que le dieron origen

    Risk of adverse pregnancy outcomes in women with periodontal disease and the effectiveness of interventions in decreasing this risk: Protocol for systematic overview of systematic reviews

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    Background: Periodontal disease is an inflammatory disease of the tissues supporting the teeth. Women who have periodontal disease while pregnant may be at risk of adverse pregnancy outcomes. Although the association between periodontal disease and adverse pregnancy outcomes has been addressed in a considerable number of systematic reviews and meta-analyses, there are important differences in the conclusions of these reviews. Systematic reviews assessing the effectivity of various therapeutic interventions to treat periodontal disease during pregnancy to try and reduce adverse pregnancy outcomes have also arrived at different conclusions. We aim to provide a systematic overview of systematic reviews comparing the frequency of adverse pregnancy outcomes between women with and without periodontal disease and/or evaluating the effect of preventive and therapeutic interventions for periodontal disease before or during pregnancy on adverse pregnancy outcomes. Methods: We will include systematic reviews reporting on studies comparing adverse pregnancy outcomes: (i) between women with or without periodontal disease before (<6 months) or during pregnancy and/or (ii) according to preventive or therapeutic interventions for periodontal disease. Eligible interventions include (combinations of) the following: oral hygiene education, use of antibiotics, subgingival scaling, and root planing. For preventive and/or therapeutic reviews, the following comparisons will be considered: no intervention, a placebo intervention, or an alternative intervent

    Exploring assessment practices of companies actively engaged with circular economy

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    An emerging research area is dedicated to developing approaches for assessing the ‘circularity’ of companies and their products, within the context of sustainability goals. However, empirical evidence on the uptake of these assessment approaches remains scarce. Using a purposive sampling, we conducted a survey receiving 155 responses and held 43 semi-structured interviews with Dutch and Italian companies active in circular economy (CE), pursuing three research aims: to explore the use of CE and sustainability assessment approaches; to study the process of developing assessment approaches; and to uncover benefits of—and barriers to—CE assessment. While we find high variability of assessment approaches, most often, companies develop tailor-made sustainability indicators and apply life cycle assessments to CE strategies. Importantly, assessment development for CE practices requires and facilitates collaboration with external stakeholders. Finally, we reflect on the paradox of standardisation versus tailoring of assessment approaches within the CE reality and recommend establishing company needs and capabilities before designing assessment approaches

    High Magnetic Field NMR Studies of LiVGe2_2O6_6, a quasi 1-D Spin S=1S = 1 System

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    We report 7^{7}Li pulsed NMR measurements in polycrystalline and single crystal samples of the quasi one-dimensional S=1 antiferromagnet LiVGe2_2O6_6, whose AF transition temperature is TN≃24.5T_{\text{N}}\simeq 24.5 K. The field (B0B_0) and temperature (TT) ranges covered were 9-44.5 T and 1.7-300 K respectively. The measurements included NMR spectra, the spin-lattice relaxation rate (T1−1T_1^{-1}), and the spin-phase relaxation rate (T2−1T_2^{-1}), often as a function of the orientation of the field relative to the crystal axes. The spectra indicate an AF magnetic structure consistent with that obtained from neutron diffraction measurements, but with the moments aligned parallel to the c-axis. The spectra also provide the TT-dependence of the AF order parameter and show that the transition is either second order or weakly first order. Both the spectra and the T1−1T_1^{-1} data show that B0B_0 has at most a small effect on the alignment of the AF moment. There is no spin-flop transition up to 44.5 T. These features indicate a very large magnetic anisotropy energy in LiVGe2_2O6_6 with orbital degrees of freedom playing an important role. Below 8 K, T1−1T_1^{-1} varies substantially with the orientation of B0B_0 in the plane perpendicular to the c-axis, suggesting a small energy gap for magnetic fluctuations that is very anisotropic.Comment: submitted to Phys. Rev.

    Model-based investigation into atmospheric freeze drying assisted by power ultrasound

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    Atmospheric freeze drying consists of a convective drying process using air at a temperature below the freezing point of the processed product, and with a very low relative humidity content. This paper focuses on the use of a simple one-dimensional model considering moving boundary vapor diffusion to describe the ultrasonic assisted atmospheric freeze-drying of foodstuffs. The case study is the drying of apple cubes (8.8 mm) at different air velocities (1, 2, 4 and 6 m/s), temperatures ( 5, 10 and 15 C), without and with (25, 50 and 75 W) power ultrasound application. By fitting the proposed diffusion model to the experimental drying kinetics, the effective diffusivity of water vapor in the dried product was estimated. The model was successfully validated by drying apple samples of different size and geometry (cubes and cylinders). Finally, a 23 factorial design of experiments revealed that the most relevant operating parameter affecting the drying time was the applied ultrasound power level.The authors acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO) and of the European Regional Development Fund (ERDF) through the project DPI2012-37466-CO3-03, the FPI fellowship (BES-2010-033460) and the EEBB-I-14-08572 fellowship granted to J.V. Santacatalina for a short stay at Politecnico di Torino.Santacatalina Bonet, JV.; Fissore, D.; CĂĄrcel CarriĂłn, JA.; Mulet Pons, A.; GarcĂ­a PĂ©rez, JV. (2015). Model-based investigation into atmospheric freeze drying assisted by power ultrasound. Journal of Food Engineering. 151:7-15. https://doi.org/10.1016/j.jfoodeng.2014.11.013S71515

    Embedded pitch adapters: a high-yield interconnection solution for strip sensors

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    A proposal to fabricate large area strip sensors with integrated, or embedded, pitch adapters is presented for the End-cap part of the Inner Tracker in the ATLAS experiment. To implement the embedded pitch adapters, a second metal layer is used in the sensor fabrication, for signal routing to the ASICs. Sensors with different embedded pitch adapters have been fabricated in order to optimize the design and technology. Inter-strip capacitance, noise, pick-up, cross-talk, signal efficiency, and fabrication yield have been taken into account in their design and fabrication. Inter-strip capacitance tests taking into account all channel neighbors reveal the important differences between the various designs considered. These tests have been correlated with noise figures obtained in full assembled modules, showing that the tests performed on the bare sensors are a valid tool to estimate the final noise in the full module. The full modules have been subjected to test beam experiments in order to evaluate the incidence of cross-talk, pick-up, and signal loss. The detailed analysis shows no indication of cross-talk or pick-up as no additional hits can be observed in any channel not being hit by the beam above 170 mV threshold, and the signal in those channels is always below 1% of the signal recorded in the channel being hit, above 100 mV threshold. First results on irradiated mini-sensors with embedded pitch adapters do not show any change in the interstrip capacitance measurements with only the first neighbors connected

    Mechanisms underlying a thalamocortical transformation during active tactile sensation

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    During active somatosensation, neural signals expected from movement of the sensors are suppressed in the cortex, whereas information related to touch is enhanced. This tactile suppression underlies low-noise encoding of relevant tactile features and the brain’s ability to make fine tactile discriminations. Layer (L) 4 excitatory neurons in the barrel cortex, the major target of the somatosensory thalamus (VPM), respond to touch, but have low spike rates and low sensitivity to the movement of whiskers. Most neurons in VPM respond to touch and also show an increase in spike rate with whisker movement. Therefore, signals related to self-movement are suppressed in L4. Fast-spiking (FS) interneurons in L4 show similar dynamics to VPM neurons. Stimulation of halorhodopsin in FS interneurons causes a reduction in FS neuron activity and an increase in L4 excitatory neuron activity. This decrease of activity of L4 FS neurons contradicts the "paradoxical effect" predicted in networks stabilized by inhibition and in strongly-coupled networks. To explain these observations, we constructed a model of the L4 circuit, with connectivity constrained by in vitro measurements. The model explores the various synaptic conductance strengths for which L4 FS neurons actively suppress baseline and movement-related activity in layer 4 excitatory neurons. Feedforward inhibition, in concert with recurrent intracortical circuitry, produces tactile suppression. Synaptic delays in feedforward inhibition allow transmission of temporally brief volleys of activity associated with touch. Our model provides a mechanistic explanation of a behavior-related computation implemented by the thalamocortical circuit

    Study of surface properties of ATLAS12 strip sensors and their radiation resistance

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    A radiation hard nĂŸ-in-p micro-strip sensor for the use in the Upgrade of the strip tracker of the ATLAS experiment at the High Luminosity Large Hadron Collider (HL-LHC) has been developed by the “ATLAS ITk Strip Sensor collaboration” and produced by Hamamatsu Photonics. Surface properties of different types of end-cap and barrel miniature sensors of the latest sensor design ATLAS12 have been studied before and after irradiation. The tested barrel sensors vary in “punchthrough protection” (PTP) structure, and the end-cap sensors, whose stereo-strips differ in fan geometry, in strip pitch and in edge strip ganging options. Sensors have been irradiated with proton fluences of up to 1 1016 neq/cm2 , by reactor neutron fluence of 1 1015 neq/cm2 and by gamma rays from 60Co up to dose of 1 MGy. The main goal of the present study is to characterize the leakage current for microdischarge breakdown voltage estimation, the inter-strip resistance and capacitance, the bias resistance and the effectiveness of PTP structures as a function of bias voltage and fluence. It has been verified that the ATLAS12 sensors have high breakdown voltage well above the operational voltage which implies that different geometries of sensors do not influence their stability. The inter-strip isolation is a strong function of irradiation fluence, however the sensor performance is acceptable in the expected range for HL-LHC. New gated PTP structure exhibits low PTP onset voltage and sharp cut-off of effective resistance even at the highest tested radiation fluence. The inter-strip capacitance complies with the technical specification required before irradiation and no radiation-induced degradation was observed. A summary of ATLAS12 sensors tests is presented including a comparison of results from different irradiation sites. The measured characteristics are compared with the previous prototype of the sensor design, ATLAS07
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